Non-Volatile Memory (NVM) devices are subject to various failures, e.g., due to imperfect manufacturing process. Such failures include, for example, word-line to substrate and word-line to word-line short or leakage, which may result in data loss in programming, reading or both.
Methods for avoiding data loss in programming NVM devices are known in the art. For example, U.S. Patent Application Publication 2013/0117606, whose disclosure is incorporated herein by reference, describes a method that includes calculating redundancy information over a set of data items, and sending the data items for storage in a memory. The redundancy information is retained only until the data items are written successfully in the memory, and then discarded. The data items are recovered using the redundancy information upon a failure in writing the data items to the memory.
U.S. Patent Application Publication 2013/0229868 describes techniques of operating a non-volatile memory so that in case data that would otherwise be lost in the case of a word line to word line short is preserved. Before writing a word line, the data from a previously written adjacent word line is read back and stored in data latches associated with the corresponding bit lines, but that are not being used for the data to be written. If a short occurs, as the data for both word lines is still in the latches, it can be written to a new location.